Many older locomotives comprise systems, such as the operator cab, the drive system (i.e., the traction motors, trucks and undercarriage of the locomotive), and brake system that are capable of continuing to provide additional years of reliable operation with minor repairs, and comprise other systems, such as the propulsion system, that are outdated, unreliable or inefficient, and thus are in need of extensive repair or replacement. Overhauling older locomotives is a complex and time-consuming process requiring the rebuilding of the engine, replacement or rewinding of the alternator, and updating of electrical components, many of which are obsolete and thus no longer commercially available. In most cases, the cost and time required to refurbish an older locomotive on a component-by-component basis is not cost-effective, thereby leaving (until the advent of applicants' invention) the purchase of a newer, complete locomotive as the only realistic and viable option. As a result, systems and components still possessing operational life are put to waste. The inventors have realized that there is a need for a reliable and cost effective system for replacing outdated, worn locomotive systems while providing for the conservation of older, yet highly functional locomotive systems.